Bug 13593 - Fix build issue with bison 3.0

Author: Dimitri John Ledkov <xnox@ubuntu.com>
Description: Cherrypick patch from NetBSD, to fix FTBFS with bison 3.0.

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/trunk@33738 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6